1. Field of the Invention
The present invention relates to a terminal and a communication control method.
2. Description of the Related Art
Carrier aggregation (CA) is adopted in a long term evolution (LTE) system. In CA, communications are performed by having a predetermined bandwidth as a basic unit (maximum 20MHz), and by using a plurality of carriers simultaneously. By using carrier aggregation (hereinafter, referred to as “CA”), it is possible to use a bandwidth wider than conventional LTE communications, and it is possible to increase communication speed and capacity. A carrier as a basic unit of CA is referred to as a component carrier (CC).
When CA is performed, a primary cell (PCell) that has high reliability for securing connectivity and a secondary cell (SCell) are set for a terminal in a CA configuration. The terminal is first connected to a PCell, and, if necessary, an SCell can be added.
Further, in an LTE system, an operation called scheduling is performed in which radio resources are assigned (allocated) to users (terminals) when performing data transmission and reception between a base station and terminals. The minimum time unit of the scheduling is called transmission time interval (TTI). One TTI is 1 ms. Further, the TTI is also referred to as a subframe. One subframe is 1 ms. (Refer to, for example, NPL 1).